https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68837
--- Comment #5 from HaoChen Gui ---
I think there are two ways avoiding sign extension for offset loading.
a. Make sure all offsets be positive. There exists backward jumps as well as
STC will reorder the basic block. So the offset might be neg
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68837
--- Comment #4 from Segher Boessenkool ---
On Power9 the lwa insn is cracked into an lwz and an extsw, just like
on older CPUs. Cracked instructions have fewer constraints on p9 than
they did on most older CPUs though (it doesn't have to be firs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68837
--- Comment #3 from David Edelsohn ---
The PR was from 2015, before Martin's improvements.
Also, sign-extend load instructions were less efficient at the time. We need
to re-examine the sequence on more recent microarchitectures.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68837
HaoChen Gui changed:
What|Removed |Added
CC||guihaoc at gcc dot gnu.org
--- Comment #2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68837
David Edelsohn changed:
What|Removed |Added
Status|UNCONFIRMED |NEW
Last reconfirmed|
